Did Claudius and Gertrude have an affair before the death of Old Hamlet?

The ghost refers to Gertrude as an “incestuous and adulterate beast". In Elizabethan England, and according to the Old Testament book of Leviticus 20:21, marrying your late husband’s brother would be considered an incestuous act (“If a man shall take his brother’s wife, it is an unclean thing.”). Thus, when Gertrude remarries Claudius she effectively is guilty of incest. The word “adultery” may refer either to a marital affair (in the modern sense) or any sexual sin (in the Elizabethan sense), including incest. For certain, Gertrude is guilty of incest. Whether or not they had an affair is ambiguous, but Shakespeare certainly spares no expense in describing their heated sexuality. Claudius and Gertrude obviously have chemistry.Does Gertrude know Claudius killed Hamlet, Sr.?I have been thinking about this question a lot lately. I do not believe this one to be as enigmatic as some may think. In my mind, the answer is ‘no’. There is no textual evidence to support the affirmative response to this question. First, she marries her husband’s killer—and act that seems unfathomable if she knows of foul play. She either doesn’t know, or she was 100% complicit. But if she were a true accomplice, there would be no reason for the ghost to instruct Hamlet to leave her sins alone (“Taint not thy mind, nor let thy soul contrive / Against thy mother aught: leave her to heaven”). Her sins, while still vile, are not as great as murder and will “prick and sting” her as she lives. Let’s face it, no one knows of King Hamlet’s murder. It takes a ghost to make this fact known. Therefore Gertrude’s only deadly sin is her “o'erhasty marriage” as a crime of incest/adultery. Likewise, she shows no signs of guilt, counter to Claudius’ guilt which “smells to heaven”. Second, she shows surprise at Hamlet’s suggestion that his father was murdered. I believe her line "As kill a king?" in the closet scene is not so much an ‘Oh crap, Hamlet knows!’ as it is a realization of the possibility that Hamlet’s seemingly mad reality might be true. Perhaps she is naïve, or perhaps in that moment she is forced to consider a possibility she has formerly repressed. Whether she is ignorant or mentally inhibited, her innocence creates a further complication which stifles Hamlet’s ability to carry out revenge. The ghost must reappear to remind Hamlet to help his mother, not hurt her. Still, Gertrude does not see the ghost. Assuming she now knows in her heart and mind that Claudius is a murderer, her attitude remains strikingly unaffected on the surface. This is partly because Hamlet instructs her to keep her distance from Claudius and be complicate in his feigned madness, and partly her own uncertainty. She lies to Claudius to protect Hamlet, telling Claudius that Hamlet "weeps for what is done" when clearly he does not. She feels guilty for the actions that lead to Polonius’ death (“so full of jealously is guilt / it spills itself in fearing to be spilt”) and the subsequent madness of Ophelia, yet still does not outwardly take sides. Unless she knows the cup is poisoned…Does Gertrude know the cup is poisoned?Since the text is ambiguous it is difficult to tell. Perhaps Gertrude drinks knowingly, trading her son’s life for her own. Perhaps she is suspicious, but ultimately unsure if the cup is poisoned, risking her life to save Hamlet from certain death. Perhaps she is unaware, oblivious to the danger that awaits her, only recognizing the truth when she is faced with death. All seem a fitting end to a Shakespearean tragedy. Most Oedipal interpretations agree that Gertrude knowingly drinks the poison, bringing her relationship with Hamlet full circle – she then becomes the nurturing mother Hamlet desires. Why does Ophelia give Gertrude rue?It is interesting that the only herb Ophelia intends for herself is rue: "...there's rue for you, and here's some for me; we may call it herb of grace o'Sundays; O, you must wear your rue with a difference." Scholars commonly agree that the rue is also meant for Gertrude. The symbolic meaning of rue is regret, but the practical application of rue is as a powerful abortifacient which can be lethally toxic. Does this explain why Gertrude married Claudius so quickly after her husband’s death? Or is the rue simply in reference to the regret and repentance? Being the Shakespeare purest that I am, I tend to lean toward the latter.

But, to discover how I deal with these questions you must come see the play!